1. Field of the Invention
This invention relates to propellants and is particularly directed to gun propellant formulations containing energetic azide compounds, to provide reduced isochoric flame temperatures and ultra-high mass impetus.
2. Description of Related Art
Various propellant formulations have evolved over the years in response to the requirements for improved gun propellant compositions which impart high velocity and penetrability to associate projectiles. For modern applications, particularly with respect to high velocity tank guns and defense interceptor systems, mass impetus levels approaching 500,000 ft-lb.sub.f /lb.sub.m or greater are desired. Such ultra-high force propellants have heretofore been dispossessed of the desirable combination of reduced isochoric flame temperatures and ultra-high mass impetus.
Another factor associated with gun propellant compositions is erosivity. Erosivity is approximately proportional to the flame temperature (T.sub.v) to the eighth power. The propellant composition JA-2, consisting essentially of 59.5 percent nitrocellulose (13.1N); 14.9 percent nitroglycerin; 24.8 percent diethyleneglycol dinitrate; and the remainder 0.8 percent additives, has a mass impetus of about 385,000 ft-lb.sub.f /lb.sub.m and an isochoric flame temperature of about 3500.degree. K. compared to a cyclotrimethylenetrinitramine (RDX) nitrocellulose-based propellant having a mass impetus of about 466,700 ft-lb.sub.f /lb.sub.m and an isochoric flame temperature of about 4300.degree. K. The RDX system is five and a half times as erosive as the JA-2 system.
The new azide systems of the present invention are about twice as erosive as the known JA-2 system, but they are substantially less erosive than known RDX systems. In addition, the new formulations of the present invention exhibit greater mass impetus and reduced isochoric flame temperatures when compared to known propellant formulations.